These Spitfire Wheels F4 Conical Full 52MM Skate Wheels are manufactured with an innovative mixture of urethane, which together with the wide-shaped Conical Shape will allow you to skate on all types of terrain. Each wheel is molded and designed to achieve and maintain good stability even at high speeds, no matter what style of skateboarding you are practicing whether on the road or on a ramp. In fact, Spitfire has always been synonymous with speed, stability and durability.